Dyeing with vat dyestuffs



PatentedDec-8, 1"942 UNITED STATE/IS PATENT] orrics "asumz DYEING WITH VAT DYESTUFFS William Robert Edward Hopkins, Simon Thomson McQueen, and Clarence Sydney Woolvin, Blackley, Manchester, England, assignors to Imperial Chemical Industries Limited, acorporation of Great Britain No Drawing. 'Application April 30, 1941, Serial No. 391,212. n Greater-annuit 2a, 1940 '5 Claims.

This invention relates to the preparation of alkaline hydrosulphite solutionsof vat dyestuffs classes, is customarily effected by first treating the dyestufi in water with suitable proportions of alkali and sodum hydrosulphite so that a solution of the leuco vat dyestuff is obtained, and then dyeing in this alkaline hydrosulphite solution of the leuco vat dyestufi.

These solutions gappear to be colloidal solutions rather than truesolutions. They are not always satisfactory for use in dyeing machines where the solution is made to circulate and pass through the textile material; nor are they always satisfactory for use in dyeing textile materials which are difiicult to penetrate, because of the closeness' of their weave, their thickness or other cause. Further, they are liable to deteriorate in dyeing properties prior to or during use. Also in some cases where the dyestufi is vatted in concentrated volume, the concentrated vat may be lacking in proper fluidity.

We have found that alkaline hydrosulphite solutions of vat dyestuffs of improved properties may be prepared by incorporating in the solution a small proportion of a condensation product as 1 further defined below. The improvement consists in improved dyeing properties or improved stability or both, and .in: some cases where the dyestuff is vatted in concentrated volume, in improvedfluidity; The improved dyeing properties I lead to better penetration and better levelling, when the solution are used with textile materials, or under dyeing conditions where penetration and/or levelling. are otherwise unsatisfactory, or when the vat dyestu'fl which is used is one of the less soluble ones.

The incorporation may be in most cases most easily made by adding the condensation product as such or in aqueous solution to the vat. -It

' can, however, be incorporated in other ways, for

instance by first incorporating it in a vat dyestuflf paste or other preparation and then using this dyestufi paste or preparation.

The said condensation products are the basic, water-soluble condensation products obtained from hexamethylenetetramine and alkyl halides containing not more than 4' carbon atoms by the processes described in British Patent No. 207,499 correspondingto U. 8. Patent 1,471,213 oi. October 16,, 1923. As described in that British patent, the products appear to be formed by the reaction of hexamethylenetetramine and the alkyl halide, followed by the hydrolysis of the reaction product and further condensation or interaction, and conversion of the product to a free base. In this specification and claims these products will be referred to as the hexamethyl-' enetetramine-alkyl halide condensation products" in which the alkyl halides contain not more than four carbon atoms. The products formed are probably aldehyde amine condensation products or. such products which have undergone further polymerisation.

One of the most convenient condensation products to .use is that which is obtained from ethyl chloride by interacting with hexamethylenetetramine in water under pressure at about 120 I C. effecting hydrolysis and condensation at the same or a higher temperature and then heating in the presence of sodium hydroxide as-described in the aforesaid British patent. Theproduct is i probably a polymerised one.

The invention accordingly comprises a process for the preparation of aqueous alkaline hydrosulphite solutions of vat dyestufis of improved properties by incorporating in the solution a small proportion of a condensation product, as

defined above.- It also comprises the dyeing of cellulosic textile materials by the process which comprises the application thereto of the improved aqueous, alkaline hydrosulphite solutions.

The proportions of condensation product which are incorporated in the vat depend upon the dyestuii used, the amount of 'water present and other circumstances. Very low proportions are generallyeflective, e. g. 1 part in 2000-10,000 P rts of water is sumcient to produce marked levelling action in most cases. The incorporation of the condensation products is very easily eflected, since the compounds are very soluble in water. As the proportion used is so small the compounds are conveniently added as solutions in .water, for instance as 12% solutions. The addition may be made before, during or after The following examples, in which parts are v by weight, illustrate but do not limit the invention.

Example 1 as parts of Caledon Jade Green xs (Colour Index No. 1101) are vetted in 1000 partsot water The dye vat prepared in Example 1, is used 2 for dyeing a closely woven cotton material, namely an unmercerised sateen. 25 parts of the sateen are dyed in thevat for '45 minutes at 45 C.

The dyed sateen is then taken out of the vat,

squeezed, oxidised by hanging in air for 15 minutes, thoroughly rinsed in cold water and then boiled for 30 minutes in a 0.3% soap solution. The resulting dyeing is characterised by excellent penetration and levelness,'belngbetter in both these respects than a dyeing obtained with ut the use of the condensation product.

I Example 3 This is the same as Example 1, except that instead of the Caledon Jade'Green there is used Caledon Brilliant Purple 2R5 (Colour Index No. 1104) and that vatting is done at 60 C. The effect of the addition of'the condensation product is to improve the vat in the same way as in Example 1.

' Example 4 This is also the same as that of Example 1, except that instead of the Caledon Jade Green XS there is used Caledon Dark Blue BMS (Colour index 1099) and that vetting is done at 50 C- The condensation product efiects an improvement similar to that in Examples 3. and 3.

' Example 5 20 parts of Caledon Blue RC (Colour Index No. 1114) containing thecondensation product from hexamethylenetetramine and ethyl chloride, and prepared as described below, are vatted in 2000 parts of water at 50 C. with 12 parts of sodium hydroxide and 5 parts of sodium hydrosulphite, concentrated powder. The resulting vat is in better condition for use in dyeing and remains: more fluid upon standing, than does a similarly prepared vat made from dyestufl without the condensation product.

The preparation containing Caledon Blue RC is made as follows. 6 parts of the condensation product from hexamethylenetetramine and ethyl chloride are added to 200 parts of an aqueous; suspension of Caledon Blue RC, containing 19 parts of the dyestuif. The two ingredients are then thoroughly mixed, either by stirring, or by treatment in' a colloid mill, so as to obtain a uniform distribution of the condensation product inthe dyestufl paste. 7

Example 6 This is similar to Example 5, except that the: preparation containing Caledon Blue RC is that which is made as described below. The vat which is obtained is similar to that obtained in Example 5.

The preparation containing Caledon' BlueRC, which is used above, is in powder form. It is made by taking 285 parts of finely groundCaledon Blue RC and 707 parts of the sodium salt of the condensation product of sulphonated naphutes.

thalene and formaldehyde, suspended in 1000 parts of water, and adding 7.5 parts, of the con-' densation product from hexamethylenetetramine and ethyl chloride. Mixing-is then eifected as in making the dyestufi preparation which is used in Example 5, and the mixture is then dried at 60 C. and ground.

Example 7 0.25 part of Caledon Jade Green XS are vatted in parts of waterat 45 C. with 2.5 parts of,

sodium hydrosulphite, concentrated powder, and 5 parts of sodium hydroxide. To the resulting vat there are then added 875 parts of water followed by 0.5 part of the condensation product of hexamethylenetetramine and butyl iodide. A vat of improved dyeing properties, especially a regards penetrating and level dyeing properties, is obtained.

Example 8 This is the same as Example 1, except that instead of 0.1 part of the condensation product of hexamethylenetetramine and ethyl chloride,

there .are used 0.15 part of the condensation product of hexamethylenetetramine and ethyl bromide. A vat of improved dyeing properties is obtained.

Example 9 0.25 part of Caledon Brilliant Purple ZRS is vetted in 125 parts of water at 60 C. with 2.5 parts of sodium hydrosulphite, concentrated powder, and 5 parts of sodium hydroxide. To the resulting vat there are added 8'75 parts of a solution containing 0.5 part of the condensation product of hexamethylenetetramine and propyl bromide, this solution being at 60 C. A vat of improved dyeing properties is obtained.

Example 10 Example 11 A cotton cheese weighing 450 parts, which has previously been well boiled out is introduced into the liquor in Example 10 and dyeing is carried out at 45 C. for about 1% hours, reversing the liquor circulation in the machine every 10 min- The dyed cheese is hydroextracted and oxidised by the passage of cold air and is then thoroughly washed free from alkali and is finally soap boiled in the Longclose machine for half an hour prior to washing and drying. The resulting dyeing is characterised by excellent penetration and levelness being better in both these respects than a dyeing obtained without the use of the condensation product.

.We claim:

1. An alkaline hydrosulphite solution of a vat dyestufl in which has been incorporated a hexamethylenetetramine-alkyl halide condensation product in which the alkyl halide contained not more than four carbon atoms.

2. An alkaline hydrosulphite solution of a vat dyestufl of the anthraquinone series in-which has been incorporated a hexamethylenetetramine-alkyl halide condensation product in which the alhi halide contained not more thanwtour carbon atoms.

3. An alkaline hydros lphite solution oi a vat dyestui! oi. the dibenzantbrone series in which has been incorporated a hexamethylenetetra- 'mine-alky1 halide condensation product in which the alkyl halide contained not more than four carbon atoms. l

4.. An alkaline hydrosulphite solution or Bz2,

m'-dimethoxy-dibenzanthrone in which has 10 been a hexamethylenetetramine-alkyl halide condensation product in which the 'alkyl halide contained not more than four carbon atoms. v

5. An alkaline hydrosulphite solution of dichloro-iaodibenzanthrone in'which has been incorporated a hexamethylenetetraminealkyl halide condensation product-in which the alkyl halide contained not more than four carbon atoms.

WILLIAM ROBERT EDWARD HOPKINS. SIMON THOMSON. McQUEEN. i CLARENCE SYDNEY WOOLVIN. 

